"These organisations have prepared suicide bombers who may target Imran Khan and the PTI rally in Islamabad. The suicide bombers may also target the PTI caravan in Lahore leaving for Islamabad rally," the report said.

The interior ministry has asked Khan to take extra security measures for himself during the rally. The ministry has also called on both the police and rangers to deal with the PTI workers in case of violence as well as for the security of the rally.

Khan said the Nawaz Sharif government would not be allowed to function after November 30 if an investigation into alleged massive rigging in the 2013 election was not launched.

"If Prime Minister Nawaz Sharif thinks he will run the government without auditing the 2013 election, he is mistaken," he said.

Khan had launched a a two-month protest campaign in August demanding that Sharif resign.